Engine/Transmission (1998.5 - 2002) follow up on 180 t-stat

[Greg Boardman-RIP]

Re: I have had great luck with the 180 T-Stat....

Originally posted by Chipstien

Now if only there was a way to get this truck into the 18's and 19's in regards to MPG.

I have figured that one out Chipstien. Let your Grandma drive your truck for say 5000 miles and check the milage then.

 

[Tom G]

Thermostats - Easy Change - But Needed?

O. K. so let’s talk about thermostats and what happened when I changed my 190 to a 180 - well not MUCH really. I can remember a few of the TDR posts back when this was a big subject. Someone said; about 2 more MPG; someone else said less horsepower going to turning the fan and finally runs cooler so engine life will be longer. Everyone of these posts are excellent because we can all learn from everyone’s experience right?



For me there was NOT a significant change in my MPG. There was a change however it was only about ½ MPG and I am not sure that was because of the changed thermostat. Of course I only have about 30 tanks of diesel (changed thermostat at about 15,000 miles) to compare against and the truck was still getting broken-in during that time. So to make this part of the story short I would say I gained some fractional or part of a mpg. I would say that the biggest change in my MPG came as the result of towing. I went from about 16. 5 to 17. 5 MPG running empty hand calculated. Also the engine runs much smoother.



How about less horsepower going to turn the fan? I will be the first to agree that when that fan engages you can really feel it. Did the thermostat help me here – well not really (some maybe) but not a whole bunch because of how I drive and where I live. Living in the desert southwest you expect hot weather. I mean 105 to 115 degrees in the summer is quite common so we are normally running the A/C about 10 months of the year. Between the heat from the A/C condensing coil in front of the radiator and the heat from the intercooler that’s enough to engage my clutch fan on a 110 degree day even if I am not towing anything. So having a 180 degree thermostat didn’t really help cut down on how frequently the fan runs in the summer. You can try this yourself. Hook up to your trailer, 5th wheel, toybox, whatever and watch the temperature gage. Try running with and without the A/C on. Next try running empty and do the same thing. In my truck the engine NEVER gets above 185 degrees but the clutch fan will still come on when the A/C is on AND my turbo is making even a small amount of boost. So while the thermostat DOES cut down on how frequently my clutch turns on in the winter months it didn’t help much during the summer or when towing. So was the $20 and 30 minutes to install the thermostat worth it – sure it was and a very simple job to do also.



Will my engine last longer. Ah this question is easy to answer. I expect my engine to last for at least another 300,000 miles. Let’s see; at 15,000 mile per year that’s about another 20 years. The Cummins will most likely outlive me by a significant margin LOL

 

[PRout]

Im in the crowd that cant tell much difference in performance.



About the only difference I can tell is the temp gauge is consistantly lower than before. I like knowing that less heat usually means less wear.



EGT's are the same, so combustion shouldnt suffer.



Fuel mileage is about the same, if anything has lost 1/2 mpg, but cant prove it, certainly hasnt gone up on average. Just went about 1525 miles on my 100 gal system, and the fuel light just came on, which is about normal. Lots of stop & go driving, so cant complain.



Staying at around 17mpg for city driving. Thats what it got before the therm.



Throttle response is about the same.



I'd say Air temps seem to make more difference in throttle response & power than coolant temps.



Maybe for someone that was right on the edge of a temp window in the cpu, the therm may make a difference (kicking them into a different timing setting), but hasnt been the magic goodie in my case.



Oh, and while pulling heavy in the desert up long grades, it doesnt really help keep temps down, once its open, it doesnt matter what its rating is, if full water flow wasnt enough before, it wont be now. Will still creep up to 200+ when overdoing the capacity of the cooling system. Example, pulling Halloran pass coming back from Vegas in 115* heat. Keeping EGT's at 1200, but Coolant temps were starting to run-away. Had to let off & go down a gear to keep coolant temps in check. 180 Thermostat didnt help. Still could use more cooling capacity IMO. At stock power its probably no problem.

 

[PRout]

And, here in the southwest the heater still gets warm pretty quick. Havent been through winter yet, but it should be ok.



Cant speak for you folks that deal with real cold. .